Saeed Pourojaghi

Department of Physics, Bu-Ali Sina University, Hamedan.

Recent Challenges to the Standard Cosmological Model 

Abstract: The standard cosmological model (ΛCDM) is considered the first and simplest model to describe the accelerated expansion of the universe. Despite its good compatibility with observational data, this model faces various theoretical and observational challenges. In this talk, I intend to discuss the latest challenges to this model. First, we will examine the redshift evolution of the free parameters of the ΛCDM model using observational data binning. This approach is significant because these parameters are mathematically and observationally considered constants, but our results show different values for them in various redshift bins. In the next part of my talk, we will present a study on the cosmological constraints of dark energy parametrizations post-DESI 2024, suggesting potential deviations from the standard ΛCDM cosmology. Our main goal is to examine the results of DESI collaborations on some extensions of the CPL approximation, known as the BA and Pade parametrizations. Finally, we will provide an analysis of the ΛCDM model using a cosmography approach, which includes recent DESI BAO observations and Type Ia supernova catalogs, including the DES-SN5YR and Pantheon+ sets.

یکشنبه  13 آبان 1403، ساعت 17:00

Sunday 3 November 2024 – 17:00 Tehran Time

Hybrid Seminar

دانشکده فیزیک – طبقه اول – کلاس فیزیک 3 /Physics Department – first floor – Room Physics 3   

https://vc.sharif.edu/ch/cosmology

گزینه ورود به صورت مهمان – Enter as a Guest